Animal life follows the rhythms of the ever-changing seasons. Nunavik’s fauna has developed adaptive strategies for both the short summers and harsh winters, in certain cases taking part in great migrations that are among the natural world’s most spectacular. Here are some of the characteristics of Nunavik’s wildlife.
Most of the birds found in Nunavik are seasonal visitors. The onset of winter puts an end to the availability of the summer plants and invertebrates that sustain migratory birds and enable them to reproduce. Since these species are not adapted to harsh winter conditions, they are obliged to fly south when cold weather arrives. One of these birds is the Canada goose.
The arrival and departure of migratory birds is closely related to the availability of resources. In spring, some species must reach their nesting sites and lay eggs before the snow melts to ensure that their young have the best resources possible when they hatch. It is important for juveniles to be sufficiently strong and developed by autumn. That is why migratory birds wait until the cold has claimed every source of food before they embark on the long voyage southward.
The permanent residents of Nunavik have a twofold challenge, for they must brave the cold as well as finding nourishment. These birds are protected with down, a layer of tiny insulating feathers between their skin and their outer feathers. This layer keeps their body heat from escaping. In intense cold, birds fluff out their feathers to further increase their ability to conserve warmth.
Birds’ feet are protected in different ways, depending on the animal’s way of life. For example, the rock ptarmigan’s feet and claws are entirely covered with feathers, since they spend most of their time on the ground looking for food. These feathers also act like snowshoes, preventing the ptarmigan from sinking into the snow. Other birds, like the raven, have hard bumps on the bottom of their feet. This keeps contact with the ground to a minimum and thus helps to prevent heat loss.
Mammals adapt in various ways, depending on their habitat. For marine mammals (seals, walruses and whales), access to air is a more serious challenge than keeping warm, since sea water never gets colder than its freezing point, -2°C. However, the sea ice creates a barrier, and these animals cannot survive without breathing holes or polynyas, which are zones of open water in the ice.
In contrast, land mammals must not only find food but also endure extreme conditions, with temperatures that can descend to -40°C. The animals’ fur, which provides excellent insulation from the cold, becomes longer and thicker in winter. The coats of caribou and polar bears consist of hollow hairs that are filled with air. Smaller mammals, like lemmings, combat the cold by staying inside tunnels under the snow, where they are sheltered from the wind and temperatures are warmer.
Finding sources of nourishment is also a major challenge for land mammals. In summer, they take advantage of the abundance of food to fatten up in preparation for the long winter. Few species choose to hibernate. It is only gestating female polar bears that enter a state of dormancy.
Large herbivores, like the caribou and muskox, survive winter by foraging for food of inferior quality. These animals lose a great deal of weight during the winter, an adaptation that protects them from famine. As the animal becomes thinner, its needs for resources are diminished. Because winter forage is low in proteins, it reduces the amount of water excreted by the animal. This means that less energy is spent melting ice and snow, which are the sole sources of water in winter.
For carnivores, winter is less difficult than it is for herbivores, since the cold conserves meat that has been left uneaten. The formation of sea ice is essential for the polar bear, since it depends on it to hunt seals. The ice is equally important for other species, such as the arctic fox and the common raven, which feed on carcasses left by predators.
Animal migration is an essential component of terrestrial, aquatic and avian life. It is defined by the displacement of more or less great distances, according to an annual or seasonal cycle. There are many types of migratory triggers, from breeding, to seasonal climate change and the search for food resources.
Migration is a fundamental element of an ecosystem’s balance, since it regulates the number of species and provides food for others.
In Nunavik, migrations occur on all scales. They may be local, such as the spawning of the Arctic char, where the fish go up a stream for breeding. They can also cover the entire territory, such as the migration of caribou hordes in search of seasonal pastures and for breeding purposes.
Marine mammals, such as beluga whales, migrate as sea ice develops, moving in the fall to areas where chances of survival and finding resources are good. They return as soon as the ice breaks, in the spring. They can also be found near the mouth of rivers.
Some species, such as the Arctic tern, travel incredible distances, spending summers in Nunavik and flying south during the winter all the way to Antarctica. This is the longest known migration in the animal kingdom, with nearly 75,000km traveled each year.
In their continuous search for food, shelter and respite from predators and insects, the caribou of Nunavik may cover up to 6 000 km in a year. No other land mammal on Earth shows such a vast migratory movement. The caribou herds of George River and Leaf River, numbering nearly a million animals, are the largest on the planet.
These two herds are the subject of a wide-ranging study investigating their numbers, state of health and migratory habits. Using a satellite monitoring system, scientists can make weekly checks on animals wearing radio-collars.
Here is an animation showing the movement of the two largest caribou herds in Nunavik over a one-year period. This animation is based on data from the Department of Natural Resources and Wildlife, Quebec and the Government of Newfoundland and Labrador.